Environmental noise reduction and cancellation for a communication device including for a wireless and cellular telephone

ABSTRACT

Various embodiments of the present invention enable a system and method for reducing or entirely canceling background or environmental noise from a voice transmission from a communications device. A communications device, such as a mobile telephone, is configured with an environmental noise compensation, correction, or counterbalanced (correction) signal generator that is connected between at least one microphone and a continuous time quadrant multiplication. Optional discrete time or digital signal processing may be applied. The original output of the at least one microphone and a compensation, correction, or counterbalanced or counter-balancing signal generated by the environmental noise compensation, correction, or counterbalanced signal generator are mixed or otherwise combined together after being received by the antenna to the receiver.

RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 11/749,927, filed May 17, 2007, and entitled“ENVIRONMENTAL NOISE REDUCTION AND CANCELLATION FOR A COMMUNICATIONDEVICE INCLUDING FOR A WIRELESS AND CELLULAR TELEPHONE,” and is herebyincorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates generally to voice communication systems,devices, telephones, and methods, and more specifically, to systems,devices, and methods that automate control in order to correct forvariable environmental noise levels and reduce or cancel theenvironmental noise after receiving the voice communication over one ora plurality of communication links.

2. Background of the Invention

Voice communication devices such as cellular telephones and wirelesstelephones and communications devices other than cellular telephoneshave become ubiquitous; they show up in almost every environment. Thesesystems and devices and their associated communication methods arereferred to by a variety of names, such as but not limited to, cellulartelephones, cell phones, mobile phones, wireless telephones in the homeand the office, and devices such as personal data assistants (PDAs) thatinclude a wireless or cellular telephone communication capability. Theyare used in the home, at the office, in the car, on a train, at theairport, at the beach, at restaurants and bars, on the street, andalmost any other imaginable venue. As might be expected, these diverseenvironments have relatively higher and lower levels of background,ambient, or environmental noise. For example, there is generally lessnoise in a quiet home than there is in a crowded bar. And, this noise ispicked up by the microphone of the communications device and if atsufficient levels, degrades the intended voice communication. Althoughthe invention described hereinafter is applicable to many differentcommunication systems and devices, examples focus on cellularcommunication networks and devices for purposes of explaining theunderlying problems and solutions.

A cellular network is a radio network made up of a number of radio cells(or just cells) each served by a fixed transmitter, normally known as abase station. These cells are used to cover different geographical areasin order to provide radio coverage over a wider geographical area thanthe area of one cell. Cellular networks are inherently asymmetric with aset of fixed main transceivers each serving a cell and a set ofdistributed (generally, but not always, mobile) transceivers whichprovide services to the network's users.

The primary requirement for a cellular network is that the each of thedistributed stations need to distinguish signals from their owntransmitter from the signals from other transmitters. There are twocommon solutions to this requirement, frequency division multiple access(FDMA) and code division multiple access (CDMA). FDMA works by using adifferent frequency for each neighboring cell. By tuning to thefrequency of a chosen cell, the distributed stations can avoid thesignal from other neighbors. The principle of CDMA is more complex, butachieves the same result; the distributed transceivers can select onecell and listen to it. Other available methods of multiplexing such aspolarization division multiple access (PDMA) and time division multipleaccess (TDMA) cannot be used to separate signals from one cell to thenext since the effects of both vary with position, making signalseparation practically impossible. Orthogonal frequency divisionmultiplex (OFDM) in principal, consists of frequencies orthogonal toeach other. Time division multiple access, however, is used incombination with either FDMA or CDMA in a number of systems to givemultiple channels within the coverage area of a single cell.

In the case of a typical taxi company, each radio has a selector knob orbutton. The knob or button acts as a channel selector and allows theradio to tune to different frequencies. As the drivers and theirvehicles move around, they change from channel to channel. The driversknow which frequency covers approximately what area, when they don't geta signal from the previously selected transmitter, they may typicallyalso try other channels until they find one which works or on which theyare able to receive or monitor communications in their local area.Usually, the taxi drivers only speak one at a time, as invited by theoperator or according to voice traffic on the channel, in a sense timedivision multiplexed system.

The wireless world comprises the following exemplary, but not limitedcommunication schemes: time based and code based. In the cellular mobileenvironment these techniques are named under TDMA (time divisionmultiple access) which comprises but not limited to the followingstandards GSM, GPRS, EDGE, IS-136, PDC, and the like; and CDMA (codedivision multiple access) which comprises but not limited to thefollowing standards: CDMA one, IS-95A, IS-95B, CDMA 2000, CDMA 1xEvDv,CDMA 1xEvDo, WCDMA, UMTS, TD-CDMA, TD-SCDMA, OFDM, WiMax, WiFi, andothers).

For the code division based standards or orthogonal frequency division,as the number of subscribers grows and average minutes per monthincrease, more and more mobile calls typically originate and terminatein noisy environments. The background or ambient noise degrades voicequality.

For the time based schemes, like GSM or GPRS or Edge schemes, improvingthe end-user voice signal-to-noise ratio (SNR), improves the listeningexperience for users of existing TDMA (time division multiple access)based networks, by improving the received speech quality by employingbackground noise reduction or cancellation at the sending ortransmitting device.

Significantly, in an on-going cellular telephone call or othercommunication received in an environment having relatively higherenvironmental noise, it is sometimes difficult for the party at thereceiving end of the connection in the noisy environment to hear whatthe transmitting party is saying. Problems associated with environmentalnoise on the transmitting or speaking person's side are an additionalproblem and addressed in the inventor's other patent applications, butnot addressed here.

With further reference to the receiver or listener side, the localambient or environmental noise in the receiving environment often“drowns out” or overwhelms the received wired, cellular, or VoIPtelephone user's signal, so that the receiving party cannot hear what isbeing said or even if they can hear it with sufficient volume the voiceor speech is not completely understandable.

Attempts to solve this problem have largely been unsuccessful. Bothsingle microphone and two microphone approaches have been attempted. Forexample, U.S. Pat. No. 6,415,034 (the “Hietanen patent”) describes theuse of a second background noise microphone located within an earphoneunit or behind an ear capsule. Digital signal processing is used tocreate a noise canceling signal which enters the speech microphone.Unfortunately, the effectiveness of the method disclosed in the Hietanenpatent is compromised by acoustical leakage, that is where ambient orenvironmental noise leaks past the ear capsule and into the speechmicrophone. The Hietanen patent also relies upon complex and powerconsuming expensive digital circuitry that may generally not be suitablefor small portable battery powered devices such as pocketable cellulartelephones. Another example is U.S. Pat. No. 5,969,838 (the “Paritskypatent”) which discloses a noise reduction system utilizing two fiberoptic microphones that are placed side-by-side next to one another.Unfortunately, the Paritsky patent discloses a system using light guidesand other relatively expensive and/or fragile components not suitablefor the rigors of cell phones and other mobile devices. Neither Paritskynor Hietanen address the need to increase capacity in cellulartelephone-based communication systems.

Therefore, there is a need in the art for a method of noise reduction orcancellation on the receiving end of a call that is robust, suitable formobile use, and inexpensive to manufacture.

SUMMARY OF THE INVENTION

The present invention provides a novel system and method for monitoringthe noise in the environment in which a cellular telephone is operatingand canceling the environmental noise so that the receiving party of thevoice communication link can more easily hear what the wired orwireless, corded or cordless, cellular, VoIP, or any other typetelephone calling user is saying.

The present invention preferably employs noise reduction and orcancellation technology that is operable to attenuate or even eliminatepre-selected portions of an audio spectrum. By monitoring the ambient orenvironmental noise in the location in which the cellular telephone isoperating and applying noise reduction and/or cancellation protocols atthe appropriate time, it is possible to significantly reduce the ambientor background noise to which the receiver to a cellular telephone callmight be subjected.

In one aspect of the invention, the invention provides a system andmethod that enhances the convenience of using a communications device,such as a wired or wireless, corded or cordless, cellular, VoIP, or anyother type, even in a location having relatively loud ambient orenvironmental noise.

In another aspect of the invention, the invention provides a system andmethod for canceling ambient or environmental noise that is present inthe environment of a party listening to a spoken voice or other contenton a communication device after it is received.

In yet another aspect of the invention, the invention monitors ambientor environmental noise at the location of the receiver or listener via asecond microphone different from the conventional transmit microphoneintended to pick up primarily spoken voice for transmission to anotherlocation, where the second microphone is primarily responsible forpicking up background, ambient, and/or environmental noise from thelocal listening environment and used to reduce, cancel, and/orcompensate or correct for local noise.

In still another aspect of the invention, the invention optionallyprovides an enable/disable switch on a communications device such as acellular telephone device to enable/disable the noise reduction and orcancellation features of the invention.

In yet another embodiment a single microphone is used for bothcollection and conversion of the local user's speech to an electricalsignal when the user is talking and as the microphone transducer forcollecting the environmental or background noise when the user islistening. A switch or switching logic may automatically or manually beused to change between the two microphone use modes.

In yet another embodiment first and second microphones are used, one forthe collection and conversion of the local user's speech to anelectrical signal when the user is talking and a second microphone forcollecting the environmental or background noise when the user islistening. No switch is needed in this mode as each microphone isprovided for its separate purpose.

In still another aspect, the invention provides a noise processingapparatus for use in a communications device

In still another aspect, the invention provides a method for cancelingnoise while listening to a spoken voice in a communications device.

These and other aspects of the present invention will become apparentupon reading the following detailed description in conjunction with theassociated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary communications device, such as awireless mobile telephone, that includes an optional second microphonefor sampling environmental noise and an optional enable/disable buttonin accordance with an embodiment of the present invention.

FIG. 2 (a)-(c) illustrate exemplary embodiments of the present inventionhaving at least a first microphone that is switched to provide bothsensing of local spoken speech and during a different period of time tosense local background or environmental noise, and a second embodimenthaving two separate microphones for these purposes and thereby eliminateany need for the switch.

FIG. 3 illustrates yet another exemplary embodiment of the presentinvention showing in particular the relationship between the inventivenoise reduction and/or cancellation block and conventional elements of atypical cellular telephone including the analog baseband/voicebandcodec.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention provides a unique background noise orenvironmental noise reduction and or cancellation feature for acommunications device such as a mobile or cellular telephone, corded orcordless telephone, conventional wire line or wireless telephone, or anyother communications device having a microphone input and a speakertransducer output and operating in an environment of background noise.While the present invention has applicability to at least these types ofcommunications devices, the principles of the present invention areparticularly applicable to all types of communications devices. Forsimplicity, the following description employs the terms “mobiletelephone” or “cellular telephone” or “communications device” asumbrella terms to describe the embodiments of the present invention, butthose skilled in the art will appreciate that the use of such term isnot to be considered limiting to the scope of the invention, which isset forth by the claims appearing at the end of this description.

FIG. 1 illustrates an exemplary mobile or stationary communicationsdevice, such as a mobile or cellular telephone 10 or any othercommunications device that comprises a first microphone 12, a speaker11, an optional display screen 13, an optional keypad 14, an optionalantenna 15, and a housing 18 having an outer surface 19. Optionally, asecond microphone 16 for either continuous time or discrete timesampling environmental noise level and an environmental noisecounterbalanced (correction) enable/disable button 17 may also beprovided. The enable/disable button or feature 17 may be exposed on thesurface of the housing or be available through a menu driven options ortelephone set up procedure, or automatic detection logic may enable thetelephone 10 to automatically identify periods where the user isspeaking and periods of time where the user is listening and switchbetween microphone configurations. This optional second microphone 16,and optional enable/disable button or feature 17 will be described morefully below relative to particular embodiments of the invention. Theselatter two elements, the second optional microphone 16 and theenable/disable button and associated circuits and/or logic, will bedescribed more fully below. Those skilled in the art will appreciatethat speaker transducer 11 could be replaced by an ear piece or by twoear pieces, head-set, or other electrical signal to acoustic transducer(not shown) that is worn by the mobile, cellular, fixed or stationary,or other telephone or communications device user. Speaker 11 is usedherein to mean the device by which sound (such as in the form of anacoustic pressure wave) is transferred from the mobile or fixedcommunications device telephone (typically in the form of a digital orelectrical signal that is converted into an acoustic or pressure wavesignal) to the user, and more specifically to one or both of a user'sear(s). Also, optional display screen 13 may optionally be a touchscreen display or other interface and display when provided, which mightoptionally incorporate keypad 14 or other interface as well as optionalenable/disable button 17. Various other different interfaces may beutilized as are known in the art.

FIG. 2 (a)-(c) illustrate an exemplary embodiments of the presentinvention including speaker transducer 11, environmental noisecompensation, correction and/or counterbalanced or counter balancingsignal circuit, or logic, or other generator 20, a continuous timequadrant multiplication (or multiplier) 22 (FIG. 2 (a)), a discrete timeprocessor 28 (FIG. 2( b)), and optional receiver 24, and optionalantenna 15.

In accordance with an embodiment of the present invention, localenvironmental, ambient, or background noise present at the listener'stelephone is cancelled or reduced before being combined with theintended voice communication received at the optional antenna 15 andreceiver 24 and delivered to the speaker 11 for reproduction as anacoustic or sound wave to the user or listener.

More specifically, in a first embodiment, antenna 15 receives a wirelesscommunication over a radio frequency communications link which isprocessed by receiver 24 to a baseband signal. This baseband signal mayfor example correspond to the output of an analog baseband/voicebandcodec 45, 47 such as illustrated in FIG. 3. The voice output from thereceiver is communicated to an environmental noise correction circuit orprocess 20 which also receives an electrical signal from microphone 12and generates correction signals based on these two inputs. It will beappreciated that the voice output of the receiver 24 may generallyinclude one or more noise components, such as noise components from thetransmit or up-link users side telephone, and/or noise from thecommunications path or link between the sending and receiving devices,however, it is not these noise components that are addressed in thepresent invention. The correction signals are communicated to an inputport of a continuous time quadrant multiplier circuit or logic 22, whichalso receives at a second input port the original voice output signalfrom the receiver as shown in FIG. 2( a).

The continuous time quadrant multiplier generates a noise reduced orcancelled signal 29 that is then output to the speaker transducer 11.

An optional fixed or dynamic gain circuit or logic block 25 mayoptionally be employed to modify a weight, gain, or amplification of oneof more of the signals in the continuous time quadrant multiplier 22.This modification of the dynamic gain may be used to adjust the amountor gain of the noise cancellation or could be turned off or shut down ifand when desired. A static or fixed gain may alternatively be utilizedbut is not preferred. In some instances, the gain applied may bepositive (e.g., amplification), negative (e.g., attenuation), or unitygain (e.g., gain is unity or no gain, amplification, or attenuation).The gain applied to each of the possible inputs may be independentlyselected. Typically at least one of the gains will be a non-unity gainat least at selected times of operation.

Environmental noise reduction and or cancellation generator or othercircuit 20, in accordance with well-known techniques, generates acorrection, compensation, or counterbalancing signal or signals that areoperable to attenuate, reduce, or altogether cancel background noisethat is not intended or desirable to be heard by the recipient party.These compensation, correction, and/or counterbalanced signals are fedinto a continuous time quadrant multiplier 22, where these signals aremixed or otherwise combined or processed with the combined signal comingdirectly from microphone 12. The result is that the environmental orbackground noise is eliminated, or at least substantially reduced,before the combined signal (environmental noise plus voice signal) issend to the user or the speaker 12 that is reproducing or transformingthe signal that is listened to and ultimately heard by the user.

Alternatively, a discreet time processor 28 such as a digital processormay be utilized in place of (or in addition to) the continuous timequadrant multiplier 22 to provide digital instead of (or in addition to)analog voice processing as shown in FIG. 2 (b). As is well known in theart of noise reduction and or cancellation, it is possible (for example,via filtering and digital signal processing techniques) to attenuate oreven cancel-out pre-selected portions of an audio signal or pre-selectedbands of a frequency spectrum, or by other means.

In one embodiment, the discrete time processor 28, such as a discretetime or digital processing block with or without signal processing isprovided to delay or slow the progress or delivery of the voice signalfrom the receiver, so that when the voice signal reaches continuous timequadrant multiplier 22 the arrival time of the voice signal and thecorrection or compensation or counterbalancing signal generated byenvironmental noise reduction and or cancellation generator 20, thesignals are synchronized as shown in FIG. 2( c). Other delay circuitsmay optionally be provided in the other path to the continuous timequadrant multiplier as may be required to achieve the desiredsynchronization.

Various techniques for adding and subtracting or otherwise combining twosignals are know in the art, such as the use of operational amplifiers,differential amplifiers, comparators, and the like circuits, and thesetechniques and circuits may be utilized here. The result is that theenvironmental noise or background noise is eliminated or cancelled, orat least substantially reduced, before the noise reduced combined signal29 (environmental noise plus voice signal) is passed to speakertransducer 11.

With reference to FIG. 3, there is illustrated an embodiment of theinvention which illustrated the relationship between the inventive noisereduction and cancellation block 30 of FIG. 2, and the otherconventional components of a typical cellular telephone receiver 24. Inthis particular embodiment, it may be appreciated that the noisereduction and/or cancellation block 30 is interposed as an interfacebetween the speaker transducer output of the analog baseband/voicebandcodec 45, 47 so that a corrected or compensated signal is sent to thecellular telephone device speaker rather than the signal that would havebeen sent by the conventional cellular telephone. Furthermore, in thesingle microphone embodiment, microphone 11 is used in two modes, afirst mode is the conventional manner of picking up voice from a userand coupling this voice signal to the analog baseband/voiceband codec45, 47 in conventional manner, and is a second mode where the microphone11 is switched to disconnect it from the analog baseband/voiceband codecblock 45, 47 and to connect it to the noise reduction and/orcancellation block of the invention.

In a alternative embodiment having two microphones, the switch is notrequired and first microphone 11 is used in conventional manner toprovide the usual voice input and second microphone 16 is used to senseand provide an environmental noise input to the noised reduction andcancellation block 30. When two microphones are utilized, theircharacteristics and placement on the telephone or other communicationsdevice may be selected to improve or optimize their performance relativeto an intended function.

It may be appreciated that noise local to the speaker's environment onthe transmission may or may not have been reduced or cancelled on thetransmission side, and that the present invention may be combined withspeaker user side noise reduction or cancellation.

In accordance with one aspect of the present invention, environmentalnoise or background noise is attenuated, reduced, or cancelled from theintended voice communication. It will be appreciated that a theoreticalgoal is to cancel all ambient or environmental voice and to attenuatenone of the speech signal, however, in practice it is inevitable thatsome environmental noise may remain and/or that some speech signal maybe attenuated. Therefore, it will be understood that references tocanceling noise refer to reduction of noise with the goal of eliminatingthe noise.

In one embodiment, the continuous time quadrant multiplier 22, twosingle ended inputs (or optionally differential inputs), and arefollowed by voltage-to-current or other signal conversion circuits thatgenerate signals suitable for input to the continuous time multipliercircuit. The product of these two signals is generated by a continuoustime multiplier circuit, followed by a sum circuit that could accept again or dynamic gain to increase (amplify) or decrease (attenuate) theoutput level for the signal cleaned from noise. This cleaned signal isreferred to as the enhanced signal in some of the result data describedhereinafter in this description. It will be appreciated that whereamplification or gain are described in decibels or db, which arelogarithmic units, multiplication in non-logarithmic terms becomes asummation in logarithmic terms.

The dynamic gain circuit or logic block 25 may optionally be employed tomodify a weight, gain, or amplification of one of more of the signals inthe continuous time quadrant multiplier 22. This way, better noisecancellation is achieved, and a cleaner output is presented. Althoughnot specifically illustration in the drawings to avoid obscuring themore significant features of the embodiments, it should be appreciatedthat the gain or dynamic gain input may be applied to the noisereduction and cancellation processor 30 in any one or combination ofseveral ways and is therefore shown as an input to the processing blockas a whole. The gain whether fixed, variable, adjustable, or dynamic maybe applied to either or both of the voice+noise or noise only inputs(either before of after the voltage-to-current conversion), to theoutput of the continuous time multiplier only or in combination withapplication to one or both of the inputs. Embodiments of the inventionmay also provide for gains of different value to be applied to any oneor combination of these signals or components processing the signals sothat appropriately weighted gains may be applied to the differentsignals to achieve the desired processing result.

Further in accordance with the present invention there is optionallyprovided an enable/disable switch 17 (FIG. 1) that is preferablyoperable to enable/disable environmental noise correction, compensation,and/or counterbalanced (signal generator 20. For example, depending onthe nature of the environmental noise in a particular environment, knownnoise reduction and or cancellation techniques might also inadvertentlyattenuate the voice signal that is intended to be transmitted. In such acase, it is or may be preferable that the noise reduction and orcancellation features of the present invention be disabled, at least fora limited period of time, until the environmental noise is such that itcan be more effectively distinguished from the voice signal andattenuated independently. For example, a mobile or fixed locationtelephone user may want to call a friend from a noisy public event(e.g., a concert or sporting event) for the main purpose of letting thefriend hear the background noise of the crowd. In such a case, theswitch 17 is preferably manipulated to disable the noise reduction andor cancellation features of the present invention.

Having now described aspects of embodiments of the inventive noisereduction and cancellation processing block 30 relative to microphonesand the other components of the communications device such as a cellulartelephone, we now describe the relationship of these processing block 30relative to a conventional cellular telephone architecture to illustratethe relationship between the inventive processing block and the analogbaseband/voiceband CODEC or other stage of a communications device thatnormally receives the electrical signal output by the microphone.

FIG. 3 illustrates a block diagram typical of the major functionalblocks of a cellular telephone of the type not having the noisereduction and cancellation processing of the invention. Thisarchitecture is described so that the manner in which the inventioninteroperates with and improves the performance may be betterunderstood.

RF section 41 includes a transmit section 42 and a receive section 43and is where the RF signal is filtered and down-converted to analogbaseband signals for the receive signal. It is also where analogbaseband signals are filtered and then up-converted and amplified to RFfor the transmit signal. Analog Baseband 45 is where analog basebandsignals from RF receiver section 44 are filtered, sampled, and digitizedbefore being fed to the Digital Signal Processing (DSP) section 46. Itis also where coded speech digital information from the DSP section aresampled and converted to analog baseband signals which are then fed tothe RF transmitter section 43. It will be understood that noradio-frequency (RF) section or antenna would be required for a wiredline implementation.

The Voiceband Codec (VoCoder) 47 is where voice speech from themicrophone 11 is digitized and coded to a certain bit rate (for example,13 kbps for GSM) using the appropriate coding scheme (balance betweenperceived quality of the compressed speech and the overall cellularsystem capacity and cost). It is also where the received voice callbinary information are decoded and converted in the speaker orspeakerphone 48.

The digital signal processor (DSP) 46 is a highly customized processordesigned to perform signal-manipulation calculations at high speed. Themicroprocessor 48 handles all of the housekeeping chores for thekeyboard and display, deals with command and control signaling with thebase station and also coordinates the rest of the functions on theboard.

The ROM, SRAM, and Flash memory chips 49 provide storage for the phone'soperating system and customizable features, such as the phone directory.The SIM card 50 belongs to this category; it stores the subscriber'sidentification number and other network information.

Power Management/DC-DC converter section 52 regulates from the battery53 all the voltages required to the different phone sections. Batterycharger 54 is responsible for charging the battery and maintaining it ina charged state.

Keypad 55 and display 13 provide an interface between a user and theinternal components and operational features of the telephone.

It will be apparent to those workers skilled in the art that theinventive noise reduction and cancellation block is interposed orcoupled between the single microphone 11 of the telephone in itsconventional configuration and the analog baseband/voiceband CODEC ofthe conventional telephone. In fact the output of the noise reductionprocessing block 30 may be seen to be a processed version of theoriginal microphone input and may connect at the same microphone inputport as in a conventional phone. Not shown in the drawing is a possibleconnection between the noise reduction processing block 30 and thebattery 53 (or the power management block 52 (depending uponimplementation) that might be needed for a cellular telephone, but maynot generally be needed for a wire lined device. The noise reductionprocessing block 30 may optionally rely on a separate power source suchas an auxiliary battery that only powers the noise reduction processingblock 30. It will also be appreciated that a wire lined device would notrequire a battery or battery charger and would receive electrical power(voltage and current) from other electrical supply sources within thedevice.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number, respectively. Additionally, thewords “herein,” “above,” “below,” and words of similar import, when usedin this application, shall refer to this application as a whole and notto any particular portions of this application.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whilesteps are presented in a given order, alternative embodiments mayperform routines having steps in a different order. The teachings of theinvention provided herein can be applied to other systems, not only thesystems described herein. The various embodiments described herein canbe combined to provide further embodiments. These and other changes canbe made to the invention in light of the detailed description.

All the above references and U.S. patents and applications areincorporated herein by reference. Aspects of the invention can bemodified, if necessary, to employ the systems, functions and concepts ofthe various patents and applications described above to provide yetfurther embodiments of the invention.

These and other changes can be made to the invention in light of theabove detailed description. In general, the terms used in the followingclaims, should not be construed to limit the invention to the specificembodiments disclosed in the specification, unless the above detaileddescription explicitly defines such terms. Accordingly, the actual scopeof the invention encompasses the disclosed embodiments and allequivalent ways of practicing or implementing the invention under theclaims.

While certain aspects of the invention are presented below in certainclaim forms, the inventors contemplate the various aspects of theinvention in any number of claim forms. Accordingly, the inventorsreserve the right to add additional claims after filing the applicationto pursue such additional claim forms for other aspects of theinvention.

The foregoing disclosure of the preferred embodiments of the presentinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be obvious to oneof ordinary skill in the art in light of the above disclosure. The scopeof the invention is to be defined only by the claims appended hereto,and by their equivalents.

Further, in describing representative embodiments of the presentinvention, the specification may have presented the method and/orprocess of the present invention as a particular sequence of steps.However, to the extent that the method or process does not rely on theparticular order of steps set forth herein, the method or process shouldnot be limited to the particular sequence of steps described. As one ofordinary skill in the art would appreciate, other sequences of steps maybe possible. Therefore, the particular order of the steps set forth inthe specification should not be construed as limitations on the claims.In addition, the claims directed to the method and/or process of thepresent invention should not be limited to the performance of theirsteps in the order written, and one skilled in the art can readilyappreciate that the sequences may be varied and still remain within thespirit and scope of the present invention.

1. A communications device, comprising: a speaker containing an input ofboth voice and environmental noise; a first transmit microphone having afirst microphone output providing a first signal containingsubstantially only environmental noise; an environmental noisecounterbalanced (correction) signal generator having (i) anenvironmental noise counterbalanced (correction) signal generator inputconnected to both the speaker input and the second microphone output and(ii) an environmental noise counterbalanced (correction) signalgenerator output; a continuous time quadrant multiplier or a discretetime processor having (i) a first continuous time quadrantmultiplication input in communication with the first input signal to thespeaker and (ii) a second continuous time quadrant multiplication inputconnected to the environmental noise counterbalanced (correction) signalgenerator output and (iii) a multiplication output; a dynamic gaincircuit for providing a dynamic gain signal to the continuous timequadrant multiplication; and a receiver having a received inputconnected to the multiplication output after receiving from the antenna;wherein environmental noise picked up by the recipient and by the secondmicrophone is processed by the environmental noise counterbalanced(correction) signal generator and wherein the environmental noise isattenuated at the speaker recipient unit after being passed trough thereceiver.
 2. The communications device of claim 1, wherein thecommunications device is a mobile telephone.
 3. The communicationsdevice of claim 1, wherein the second microphone is spatially distantfrom the communications device.
 4. The communications device of claim 1,further comprising a discrete time unit or processing block with orwithout signal processing interposed between the first microphone andthe continuous time quadrant multiplication.
 5. The communicationsdevice of claim 1, further comprising an enable/disable switch forenabling/disabling the environmental noise counterbalanced (correction)signal generator.
 6. The communications device of claim 1, furthercomprising a second microphone, different from the first transmitmicrophone, having a second microphone output providing a second signalcontaining substantially only environmental noise.
 7. A noisecompensation device for a communications apparatus, comprising: areceive input port for receiving a remote user's spoken voice electricalsignal and optionally a component of environmental noise signal from thespeakers location; a microphone for receiving an acoustic air pressureinput signal at a location including at least a component of localenvironmental noise at the speaker's location and for converting theacoustic air pressure input signal into a time varying electrical signalrepresenting the acoustic air pressure input signal at the location; aspeaker transducer for converting an electrical signal representing atime sequence of sounds into a time varying acoustical signal within ahuman hearing audio frequency range; a first microphone transducer forconverting an audio frequency range signal existing in a localenvironment of the communications apparatus into an electrical signalrepresenting the local audio frequency range signal from the localenvironment; an environmental noise correction or compensation signalgenerator having: (i) an environmental noise correction or compensationsignal generator input port for receiving at least a signal derived fromthe first microphone output, and (ii) an environmental noise correctionor compensation signal output port for communicating an environmentalnoise correction or compensation output signal; a continuous timequadrant multiplier or a discrete time processor having: (i) a firstmultiplier input in communication with the first input signal to thespeaker, and (ii) a second multiplier input connected to theenvironmental noise counterbalanced (correction) signal generator outputand (iii) a multiplication output; and a receiver having a receivedinput connected to the multiplication output after receiving from theantenna, wherein environmental noise picked up by the recipient and bythe second microphone is processed by the environmental noisecounterbalanced (correction) signal generator and wherein theenvironmental noise is attenuated at the speaker recipient unit afterbeing passed trough the receiver.
 8. A noise compensation device as inclaim 7, further comprising: a second microphone, different from thetransmit microphone, having a microphone output providing a secondsignal containing substantially only environmental noise.
 9. A noisecompensation device, comprising: a first microphone generating a noisesignal output; an environmental and ambient noise correction circuithaving a first input for receiving the noise signal from the firstmicrophone and a second input for a voice signal from a receiver andgenerating a correction signal from the first and second inputs; acontinuous time quadrant multiplier or a discrete time processor havinga first input for receiving the correction signal output by theenvironmental noise correction circuit and a second input for receivingthe voice signal from the receiver and generating an output signal thatis a noise reduced version of the voice signal; and a dynamic gaincircuit for modifying a gain of a component of the continuous timequadrant multiplier.
 10. A noise compensation device as in claim 9,further comprising a switch for switching the first microphone between avoice sensing mode during a period of speech and a noise sensing modeduring periods of listening.
 11. A noise compensation device as in claim9, further comprising the receiver generating the voice signal.
 12. Anoise compensation device as in claim 9, further comprising a discretetime processor receiving the voice signal from the receiver andperforming a discrete time processing operation on the voice signalbefore providing it to the continuous time quadrant multiplier.
 13. Anoise compensation device as in claim 9, further comprising a secondmicrophone exclusively for generating a noise signal during periods ofnon-speech.
 14. A method for performing a noise compensation in adevice, the method comprising: generating a noise signal output from afirst microphone; receiving a voice signal; generating a correctionsignal from the received noise signal and the received voice signal; andperforming a continuous time quadrant multiplication or a discrete timeprocessing on the correction signal and the voice signal and generatingan output signal that is a noise reduced version of the voice signal.15. A method according to claim 14, further comprising performing adynamic gain modification for a gain of a component of the continuoustime quadrant multiplication.
 16. A method according to claim 14,wherein the device comprises a cellular telephone.
 17. A communicationsdevice according to claim 11, wherein the communications devicecomprises a cellular telephone.
 18. A communications device according toclaim 11, wherein the communications device comprises a wirelesstelephone.